Abstract: Environmental barrier coatings for high temperature ceramic components including a bond coat layer; an optional silica layer; and at least one transition layer including: from about 85% to about 100% by volume of the transition layer of a primary transition material including a rare earth disilicate, or a doped rare earth disilicate; and from 0% to about 15% by volume of the transition layer of a secondary material selected from Fe2O3, iron silicates, rare earth iron oxides, Al2O3, mullite, rare earth aluminates, rare earth aluminosilicates, TiO2, rare earth titanates, Ga2O3, rare earth gallates, NiO, nickel silicates, rare earth nickel oxides, Lnb metals, Lnb2O3, Lnb2Si2O7, Lnb2SiO5, borosilicate glass, alkaline earth silicates, alkaline earth rare earth oxides, alkaline earth rare earth silicates, and mixtures thereof; where the transition layer is applied to the component as a slurry including at least an organic solvent, the primary transition material and at least one slurry sintering aid, and where a re

Abstract: Components having an environmental barrier coating and a sintered layer overlying the environmental barrier coating, the sintered layer defining an outer surface having a lower surface roughness than the environmental barrier coating. The sintered layer is formed from a slurry applied to and then sintered on the environmental barrier coating. The sintered layer comprises a primary material, at least one sintering aid dissolved in the primary material, and optionally a secondary material. The sintering aid contains at least one doping composition. The primary material is a rare earth disilicate or a rare earth monosilicate and is doped with the doping composition so as to be either a doped rare earth disilicate or a doped rare earth monosilicate. The optional secondary material is a reaction product of the primary material and any of the sintering aid not dissolved in the primary material.

Abstract: Environmental barrier coatings for high temperature ceramic components. The barrier coatings include a bond coat layer containing silicon, an optional silica layer, at least one transition layer containing about 85% to about 100% by volume of a primary transition material comprising mullite, BSAS, or a mullite/BSAS mixture; an outer layer containing about 85% to about 100% by volume of a primary outer material comprising BSAS; and at least one of a sintering aid and a secondary material in the transition layer and/or outer layer. The secondary material is a reaction product of the sintering aid and at least one of the primary transition material and the primary outer material.

Abstract: Slurry compositions for making an environmental barrier coating including from about 9 wt % to about 81 wt % water; from about 3 wt % to about 72 wt % primary material; and from about 0.1 wt % to about 18 wt % slurry sintering aid, and environmental barrier coatings including such compositions.

Abstract: Organic solvent based slurry compositions for making an environmental barrier coating including from about 6.8 wt % to about 96.1 wt % solvent; from about 3.9 wt % to about 93.2 wt % primary material; and from about 0.01 wt % to about 20 wt % slurry sintering aid.

Abstract: Methods or making an environmental barrier coating using a sintering aid including combining at least water, a primary transition material selected from mullite, BSAS, or a mullite/BSAS mixture, and a slurry sintering aid to produce a transition layer slurry; applying the transition layer slurry to a ceramic component; combining at least water, and a primary outer material of BSAS to produce an outer layer slurry; applying the outer layer slurry to the component having the applied transition layer slurry; and sintering the component to produce the environmental barrier coating having at least a transition layer and an outer layer where the transition layer comprises a porosity of from 0% to about 30% by volume of the transition layer, and the outer layer comprises a porosity of from 0% to about 15% by volume of the outer layer.

Abstract: Methods for making an environmental barrier coating using a sintering aid involving: applying a bond coat layer to the ceramic component; combining at least water and a primary transition material selected from a rare earth disilicate or a doped rare earth disilicate to produce a transition layer slurry; applying the transition layer slurry to the bond coat layer; infiltrating a sol-gel solution comprising at least one sintering aid into the applied slurry; and sintering the component to produce the environmental barrier coating having at least the bond coat layer and a transition layer formed from the transition layer slurry during sintering. During sintering the sintering aid dopes the primary transition material with at least one doping composition.

Abstract: Methods for making an environmental barrier coating using a sintering aid including combining at least an organic solvent and a primary transition material to produce a transition layer slurry; applying a bond coat layer and then the transition layer slurry to the component; drying the applied transition layer slurry; infiltrating into the dried transition layer slurry a sol-gel solution containing an aqueous or organic solvent solution of, respectively, a water-soluble or solvent-soluble salt sintering aid; and sintering the infiltrated transition layer slurry to produce the environmental barrier coating having at least the bond coat layer and a transition layer; wherein during sintering a reaction between the primary transition material and the sintering aid results in the transition layer having a porosity of from 0% to about 15% by volume of the transition layer.

Abstract: Methods for making an environmental barrier coating using a sintering aid involving: applying a bond coat layer to the ceramic component; combining at least an organic solvent and a primary transition material selected from a rare earth disilicate or a doped rare earth disilicate to produce a transition layer slurry; applying at least the transition layer slurry, and optionally an outer layer slurry and/or a compliant layer slurry to the component; and sintering the component to produce the environmental barrier coating. The sintering step causes a reaction between a slurry sintering aid and constituents of at least one of the transition, outer and compliant layers to form a secondary material and reduce porosity in the coating.

Abstract: Methods for making an environmental barrier coating using a sintering aid involving: applying a bond coat layer to the ceramic component; combining at least water and a primary transition material selected from a rare earth disilicate or a doped rare earth disilicate to produce a transition layer slurry; applying at least the transition layer slurry, and optionally an outer layer slurry and/or compliant layer slurry to the component; and sintering the component to produce the environmental barrier coating. The sintering step causes a reaction between a slurry sintering aid and constituents of at least one of the transition, outer and compliant layers to form a secondary material and reduce porosity in the coating.

Abstract: Methods for improving surface roughness of an environmental barrier coating. The methods include providing a component having a plasma sprayed environmental barrier coating, applying an outer layer repair slurry to the environmental barrier coating of the component, drying the environmental barrier coating having the applied outer layer repair slurry, and sintering the component to produce a component having an improved surface roughness. The outer layer repair slurry includes water, a primary outer material of BSAS, and a slurry sintering aid selected from rare earth nitrate, rare earth acetate, rare earth chloride, rare earth oxide, ammonium phosphate, phosphoric acid, polyvinyl phosphonic acid, and combinations thereof.

Abstract: Methods of making components having calcium magnesium aluminosilicate (CMAS) mitigation capability include providing a component, applying an environmental barrier coating to the component, where the environmental barrier coating includes a CMAS mitigation composition selected from the group consisting of zinc aluminate spinel, alkaline earth zirconates, alkaline earth hafnates, rare earth gallates, beryl, and combinations thereof.

Abstract: Environmental barrier coatings for high temperature ceramic components including a bond coat layer; an optional silica layer; and at least one transition layer including: from about 85% to about 100% by volume of the transition layer of a primary transition material including a rare earth disilicate, or a doped rare earth disilicate; and from 0% to about 15% by volume of the transition layer of a secondary material selected from Fe2O3, iron silicates, rare earth iron oxides, Al2O3, mullite, rare earth aluminates, rare earth aluminosilicates, TiO2, rare earth titanates, Ga2O3, rare earth gallates, NiO, nickel silicates, rare earth nickel oxides, Lnb metals, Lnb2O3, Lnb2Si2O7, Lnb2SiO5, borosilicate glass, alkaline earth silicates, alkaline earth rare earth oxides, alkaline earth rare earth silicates, and mixtures thereof; where the transition layer is applied to the component as a slurry including at least an organic solvent, the primary transition material and at least one slurry sintering aid, and where a re

Abstract: An environmental barrier coating comprises at least one transition layer made from a transition layer slurry comprising from about 1 wt % to about 99.9 wt % water, from about 0.1 wt % to about 72 wt % primary transition material, from about 0.1 wt % to about 25 wt % slurry sintering aid, optionally, any one or more of an outer layer made from an outer layer slurry comprising from about 1 wt % to about 99.9 wt % water and from about 0.1 wt % to about 72 wt % primary outer material, and a compliant layer made from a compliant layer slurry comprising from about 1 wt % to about 99.9 wt % water and from about 0.1 wt % to about 72 wt % primary compliant material.

Abstract: Components having an environmental barrier coating and a sintered layer overlying the environmental barrier coating, the sintered layer defining an outer surface having a lower surface roughness than the environmental barrier coating. The sintered layer is formed from a slurry applied to and then sintered on the environmental barrier coating. The sintered layer comprises a primary material, at least one sintering aid dissolved in the primary material, and optionally a secondary material. The sintering aid contains at least one doping composition. The primary material is a rare earth disilicate or a rare earth monosilicate and is doped with the doping composition so as to be either a doped rare earth disilicate or a doped rare earth monosilicate. The optional secondary material is a reaction product of the primary material and any of the sintering aid not dissolved in the primary material.

Abstract: Methods for improving surface roughness of an environmental barrier coating involving providing a component having a plasma sprayed environmental barrier coating; applying a slurry to the environmental barrier coating of the component, the slurry being a transition layer slurry or an outer layer slurry; drying the environmental barrier coating having the applied slurry; and sintering the component to produce a component having an improved surface roughness wherein the slurry includes water; a primary transition material, or a primary outer material; and a slurry sintering aid.

Abstract: Methods of making components having calcium magnesium aluminosilicate (CMAS) mitigation capability involving providing a component; applying an environmental barrier coating to the component, the environmental barrier coating having a separate CMAS mitigation layer including a CMAS mitigation composition selected from rare earth elements, rare earth oxides, zirconia, hafnia partially or fully stabilized with alkaline earth or rare earth elements, zirconia partially or fully stabilized with alkaline earth or rare earth elements, magnesium oxide, cordierite, aluminum phosphate, magnesium silicate, and combinations thereof.

Abstract: Calcium magnesium aluminosilicate (CMAS) mitigation compositions selected from rare earth elements, rare earth oxides, zirconia, hafnia partially or fully stabilized with alkaline earth or rare earth elements, zirconia partially or fully stabilized with alkaline earth or rare earth elements, magnesium oxide, cordierite, aluminum phosphate, magnesium silicate, and combinations thereof when the CMAS mitigation composition is included as a separate CMAS mitigation layer in an environmental barrier coating for a high temperature substrate component.

Abstract: Water based slurry compositions for making an environmental barrier coating including from about 1 wt % to about 99.9 wt % water; from about 0.1 wt % to about 72 wt % primary material; and from about 0.1 wt % to about 25 wt % slurry sintering aid.

Abstract: Methods of making components having calcium magnesium aluminosilicate (CMAS) mitigation capability including providing a component; applying an environmental barrier coating to the component, the environmental barrier coating having a separate CMAS mitigation layer including a CMAS mitigation composition selected from the group consisting of zinc aluminate spinel, alkaline earth zirconates, alkaline earth hafnates, rare earth gallates, beryl, and combinations thereof.